Postion v time, Velocity v T and Acceleration v T Math Model Variable Help

AI Thread Summary
The discussion revolves around clarifying the physical quantities represented by variables in three mathematical models related to position, velocity, and acceleration. The Position vs Time model is expressed as y=Ax^2+Bx+C, where y is position, A is not velocity but rather related to acceleration, B represents the initial position, and C is still unidentified. The Velocity vs Time model is y=mx+b, where y is velocity, m is acceleration, and b is the initial velocity, but the initial position reference is incorrect. The Acceleration vs Time model is y=A*exp(-Cx)+B, where y is acceleration, A represents jerk, and B should also relate to acceleration rather than position. The need for accurate comparisons with kinematic equations is emphasized to correctly identify the variables.
EHSPhysics
Messages
1
Reaction score
0
1. I have three equations that were generated by logger pro when I inputted all my gathered data for an acceleration project and I need to state what physical quantity each variable represents. I have gotten most of them. I am mainly concerned about the variables A B and C on the math models. Any info would be great

2.
1)Position vs Time Math Model:
• Position vs Time: y=Ax^2+Bx+C
• y=position, A=velocity, x=time, b=starting position, c=_________________
2) Velocity vs Time Math Model:
• y=mx+b.
• y=velocity, m=acceleration, x=time, b=starting position.
3) Acceleration vs Time Math Model:
• y=A*exp(-Cx)+B
• y= acceleration, A=Jerk (acceleration/time) x=time, b=starting position and
c=__________________


Thanks
EHS Physics
 
Physics news on Phys.org
Welcome to Physics Forums.
EHSPhysics said:
1. I have three equations that were generated by logger pro when I inputted all my gathered data for an acceleration project and I need to state what physical quantity each variable represents. I have gotten most of them. I am mainly concerned about the variables A B and C on the math models. Any info would be great

2.
1)Position vs Time Math Model:
• Position vs Time: y=Ax^2+Bx+C
• y=position, A=velocity, x=time, b=starting position, c=_________________
I would compare the equation with the kinematic equation that gives position as a function of time. You're correct about x and y, but A and B are wrong.

2) Velocity vs Time Math Model:
• y=mx+b.
• y=velocity, m=acceleration, x=time, b=starting position.
Not entirely correct. This one needs to be compared with the equation that gives velocity vs. time.
3) Acceleration vs Time Math Model:
• y=A*exp(-Cx)+B
• y= acceleration, A=Jerk (acceleration/time) x=time, b=starting position and
c=__________________
I'm not familiar with what equation this is to be compared to, but something is definitely wrong. If y is an acceleration, then B would have to have the same units as acceleration. So B cannot be the starting position. Can you find the appropriate acceleration-vs-time equation in your class notes or textbook, and list it here?
 
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top